All sprays follow the same basic method to determine the area affected, each odd layer adds the outside bits to the layer, while the even layers are layers of the same size as the previous odd layer. Thus a change to the range of a spray effect may be very minimal or may be a near game changing effect. When homebrewing a power, remember that sprays larger than 6 or 7 can become incredibly destructive and may cause some encounters to be extremely easy if a player is using it, or if a dragon is using a breath attack with a large range he/she can easily destroy everything before him/her.

The most realistic conversion is the change of a dragon's breath weapon to a spray with the same range modifier. This may make the breath weapon less destructive, but if the attack is too weak, consider increasing the damage modifier by small amounts.